<!DOCTYPE html><html><head>
      <title>6&#x7EC6;&#x8BF4;&#x51FD;&#x6570;</title>
      <meta charset="utf-8">
      <meta name="viewport" content="width=device-width, initial-scale=1.0">
      
      <link rel="stylesheet" href="file:///C:\Users\Administrator\.vscode\extensions\shd101wyy.markdown-preview-enhanced-0.4.3\node_modules\@shd101wyy\mume\dependencies\katex\katex.min.css">
      
      

      
      
      
      
      
      

      <style>
      /**
 * prism.js Github theme based on GitHub's theme.
 * @author Sam Clarke
 */
code[class*="language-"],
pre[class*="language-"] {
  color: #333;
  background: none;
  font-family: Consolas, "Liberation Mono", Menlo, Courier, monospace;
  text-align: left;
  white-space: pre;
  word-spacing: normal;
  word-break: normal;
  word-wrap: normal;
  line-height: 1.4;

  -moz-tab-size: 8;
  -o-tab-size: 8;
  tab-size: 8;

  -webkit-hyphens: none;
  -moz-hyphens: none;
  -ms-hyphens: none;
  hyphens: none;
}

/* Code blocks */
pre[class*="language-"] {
  padding: .8em;
  overflow: auto;
  /* border: 1px solid #ddd; */
  border-radius: 3px;
  /* background: #fff; */
  background: #f5f5f5;
}

/* Inline code */
:not(pre) > code[class*="language-"] {
  padding: .1em;
  border-radius: .3em;
  white-space: normal;
  background: #f5f5f5;
}

.token.comment,
.token.blockquote {
  color: #969896;
}

.token.cdata {
  color: #183691;
}

.token.doctype,
.token.punctuation,
.token.variable,
.token.macro.property {
  color: #333;
}

.token.operator,
.token.important,
.token.keyword,
.token.rule,
.token.builtin {
  color: #a71d5d;
}

.token.string,
.token.url,
.token.regex,
.token.attr-value {
  color: #183691;
}

.token.property,
.token.number,
.token.boolean,
.token.entity,
.token.atrule,
.token.constant,
.token.symbol,
.token.command,
.token.code {
  color: #0086b3;
}

.token.tag,
.token.selector,
.token.prolog {
  color: #63a35c;
}

.token.function,
.token.namespace,
.token.pseudo-element,
.token.class,
.token.class-name,
.token.pseudo-class,
.token.id,
.token.url-reference .token.variable,
.token.attr-name {
  color: #795da3;
}

.token.entity {
  cursor: help;
}

.token.title,
.token.title .token.punctuation {
  font-weight: bold;
  color: #1d3e81;
}

.token.list {
  color: #ed6a43;
}

.token.inserted {
  background-color: #eaffea;
  color: #55a532;
}

.token.deleted {
  background-color: #ffecec;
  color: #bd2c00;
}

.token.bold {
  font-weight: bold;
}

.token.italic {
  font-style: italic;
}


/* JSON */
.language-json .token.property {
  color: #183691;
}

.language-markup .token.tag .token.punctuation {
  color: #333;
}

/* CSS */
code.language-css,
.language-css .token.function {
  color: #0086b3;
}

/* YAML */
.language-yaml .token.atrule {
  color: #63a35c;
}

code.language-yaml {
  color: #183691;
}

/* Ruby */
.language-ruby .token.function {
  color: #333;
}

/* Markdown */
.language-markdown .token.url {
  color: #795da3;
}

/* Makefile */
.language-makefile .token.symbol {
  color: #795da3;
}

.language-makefile .token.variable {
  color: #183691;
}

.language-makefile .token.builtin {
  color: #0086b3;
}

/* Bash */
.language-bash .token.keyword {
  color: #0086b3;
}

/* highlight */
pre[data-line] {
  position: relative;
  padding: 1em 0 1em 3em;
}
pre[data-line] .line-highlight-wrapper {
  position: absolute;
  top: 0;
  left: 0;
  background-color: transparent;
  display: block;
  width: 100%;
}

pre[data-line] .line-highlight {
  position: absolute;
  left: 0;
  right: 0;
  padding: inherit 0;
  margin-top: 1em;
  background: hsla(24, 20%, 50%,.08);
  background: linear-gradient(to right, hsla(24, 20%, 50%,.1) 70%, hsla(24, 20%, 50%,0));
  pointer-events: none;
  line-height: inherit;
  white-space: pre;
}

pre[data-line] .line-highlight:before, 
pre[data-line] .line-highlight[data-end]:after {
  content: attr(data-start);
  position: absolute;
  top: .4em;
  left: .6em;
  min-width: 1em;
  padding: 0 .5em;
  background-color: hsla(24, 20%, 50%,.4);
  color: hsl(24, 20%, 95%);
  font: bold 65%/1.5 sans-serif;
  text-align: center;
  vertical-align: .3em;
  border-radius: 999px;
  text-shadow: none;
  box-shadow: 0 1px white;
}

pre[data-line] .line-highlight[data-end]:after {
  content: attr(data-end);
  top: auto;
  bottom: .4em;
}html body{font-family:"Helvetica Neue",Helvetica,"Segoe UI",Arial,freesans,sans-serif;font-size:16px;line-height:1.6;color:#333;background-color:#fff;overflow:initial;box-sizing:border-box;word-wrap:break-word}html body>:first-child{margin-top:0}html body h1,html body h2,html body h3,html body h4,html body h5,html body h6{line-height:1.2;margin-top:1em;margin-bottom:16px;color:#000}html body h1{font-size:2.25em;font-weight:300;padding-bottom:.3em}html body h2{font-size:1.75em;font-weight:400;padding-bottom:.3em}html body h3{font-size:1.5em;font-weight:500}html body h4{font-size:1.25em;font-weight:600}html body h5{font-size:1.1em;font-weight:600}html body h6{font-size:1em;font-weight:600}html body h1,html body h2,html body h3,html body h4,html body h5{font-weight:600}html body h5{font-size:1em}html body h6{color:#5c5c5c}html body strong{color:#000}html body del{color:#5c5c5c}html body a:not([href]){color:inherit;text-decoration:none}html body a{color:#08c;text-decoration:none}html body a:hover{color:#00a3f5;text-decoration:none}html body img{max-width:100%}html body>p{margin-top:0;margin-bottom:16px;word-wrap:break-word}html body>ul,html body>ol{margin-bottom:16px}html body ul,html body ol{padding-left:2em}html body ul.no-list,html body ol.no-list{padding:0;list-style-type:none}html body ul ul,html body ul ol,html body ol ol,html body ol ul{margin-top:0;margin-bottom:0}html body li{margin-bottom:0}html body li.task-list-item{list-style:none}html body li>p{margin-top:0;margin-bottom:0}html body .task-list-item-checkbox{margin:0 .2em .25em -1.8em;vertical-align:middle}html body .task-list-item-checkbox:hover{cursor:pointer}html body blockquote{margin:16px 0;font-size:inherit;padding:0 15px;color:#5c5c5c;border-left:4px solid #d6d6d6}html body blockquote>:first-child{margin-top:0}html body blockquote>:last-child{margin-bottom:0}html body hr{height:4px;margin:32px 0;background-color:#d6d6d6;border:0 none}html body table{margin:10px 0 15px 0;border-collapse:collapse;border-spacing:0;display:block;width:100%;overflow:auto;word-break:normal;word-break:keep-all}html body table th{font-weight:bold;color:#000}html body table td,html body table th{border:1px solid #d6d6d6;padding:6px 13px}html body dl{padding:0}html body dl dt{padding:0;margin-top:16px;font-size:1em;font-style:italic;font-weight:bold}html body dl dd{padding:0 16px;margin-bottom:16px}html body code{font-family:Menlo,Monaco,Consolas,'Courier New',monospace;font-size:.85em !important;color:#000;background-color:#f0f0f0;border-radius:3px;padding:.2em 0}html body code::before,html body code::after{letter-spacing:-0.2em;content:"\00a0"}html body pre>code{padding:0;margin:0;font-size:.85em !important;word-break:normal;white-space:pre;background:transparent;border:0}html body .highlight{margin-bottom:16px}html body .highlight pre,html body pre{padding:1em;overflow:auto;font-size:.85em !important;line-height:1.45;border:#d6d6d6;border-radius:3px}html body .highlight pre{margin-bottom:0;word-break:normal}html body pre code,html body pre tt{display:inline;max-width:initial;padding:0;margin:0;overflow:initial;line-height:inherit;word-wrap:normal;background-color:transparent;border:0}html body pre code:before,html body pre tt:before,html body pre code:after,html body pre tt:after{content:normal}html body p,html body blockquote,html body ul,html body ol,html body dl,html body pre{margin-top:0;margin-bottom:16px}html body kbd{color:#000;border:1px solid #d6d6d6;border-bottom:2px solid #c7c7c7;padding:2px 4px;background-color:#f0f0f0;border-radius:3px}@media print{html body{background-color:#fff}html body h1,html body h2,html body h3,html body h4,html body h5,html body h6{color:#000;page-break-after:avoid}html body blockquote{color:#5c5c5c}html body pre{page-break-inside:avoid}html body table{display:table}html body img{display:block;max-width:100%;max-height:100%}html body pre,html body code{word-wrap:break-word;white-space:pre}}.markdown-preview{width:100%;height:100%;box-sizing:border-box}.markdown-preview .pagebreak,.markdown-preview .newpage{page-break-before:always}.markdown-preview pre.line-numbers{position:relative;padding-left:3.8em;counter-reset:linenumber}.markdown-preview pre.line-numbers>code{position:relative}.markdown-preview pre.line-numbers .line-numbers-rows{position:absolute;pointer-events:none;top:1em;font-size:100%;left:0;width:3em;letter-spacing:-1px;border-right:1px solid #999;-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none;user-select:none}.markdown-preview pre.line-numbers .line-numbers-rows>span{pointer-events:none;display:block;counter-increment:linenumber}.markdown-preview pre.line-numbers .line-numbers-rows>span:before{content:counter(linenumber);color:#999;display:block;padding-right:.8em;text-align:right}.markdown-preview .mathjax-exps .MathJax_Display{text-align:center !important}.markdown-preview:not([for="preview"]) .code-chunk .btn-group{display:none}.markdown-preview:not([for="preview"]) .code-chunk .status{display:none}.markdown-preview:not([for="preview"]) .code-chunk .output-div{margin-bottom:16px}.scrollbar-style::-webkit-scrollbar{width:8px}.scrollbar-style::-webkit-scrollbar-track{border-radius:10px;background-color:transparent}.scrollbar-style::-webkit-scrollbar-thumb{border-radius:5px;background-color:rgba(150,150,150,0.66);border:4px solid rgba(150,150,150,0.66);background-clip:content-box}html body[for="html-export"]:not([data-presentation-mode]){position:relative;width:100%;height:100%;top:0;left:0;margin:0;padding:0;overflow:auto}html body[for="html-export"]:not([data-presentation-mode]) .markdown-preview{position:relative;top:0}@media screen and (min-width:914px){html body[for="html-export"]:not([data-presentation-mode]) .markdown-preview{padding:2em calc(50% - 457px + 2em)}}@media screen and (max-width:914px){html body[for="html-export"]:not([data-presentation-mode]) .markdown-preview{padding:2em}}@media screen and (max-width:450px){html body[for="html-export"]:not([data-presentation-mode]) .markdown-preview{font-size:14px !important;padding:1em}}@media print{html body[for="html-export"]:not([data-presentation-mode]) #sidebar-toc-btn{display:none}}html body[for="html-export"]:not([data-presentation-mode]) #sidebar-toc-btn{position:fixed;bottom:8px;left:8px;font-size:28px;cursor:pointer;color:inherit;z-index:99;width:32px;text-align:center;opacity:.4}html body[for="html-export"]:not([data-presentation-mode])[html-show-sidebar-toc] #sidebar-toc-btn{opacity:1}html body[for="html-export"]:not([data-presentation-mode])[html-show-sidebar-toc] .md-sidebar-toc{position:fixed;top:0;left:0;width:300px;height:100%;padding:32px 0 48px 0;font-size:14px;box-shadow:0 0 4px rgba(150,150,150,0.33);box-sizing:border-box;overflow:auto;background-color:inherit}html body[for="html-export"]:not([data-presentation-mode])[html-show-sidebar-toc] .md-sidebar-toc::-webkit-scrollbar{width:8px}html body[for="html-export"]:not([data-presentation-mode])[html-show-sidebar-toc] .md-sidebar-toc::-webkit-scrollbar-track{border-radius:10px;background-color:transparent}html body[for="html-export"]:not([data-presentation-mode])[html-show-sidebar-toc] .md-sidebar-toc::-webkit-scrollbar-thumb{border-radius:5px;background-color:rgba(150,150,150,0.66);border:4px solid rgba(150,150,150,0.66);background-clip:content-box}html body[for="html-export"]:not([data-presentation-mode])[html-show-sidebar-toc] .md-sidebar-toc a{text-decoration:none}html body[for="html-export"]:not([data-presentation-mode])[html-show-sidebar-toc] .md-sidebar-toc ul{padding:0 1.6em;margin-top:.8em}html body[for="html-export"]:not([data-presentation-mode])[html-show-sidebar-toc] .md-sidebar-toc li{margin-bottom:.8em}html body[for="html-export"]:not([data-presentation-mode])[html-show-sidebar-toc] .md-sidebar-toc ul{list-style-type:none}html body[for="html-export"]:not([data-presentation-mode])[html-show-sidebar-toc] .markdown-preview{left:300px;width:calc(100% -  300px);padding:2em calc(50% - 457px -  150px);margin:0;box-sizing:border-box}@media screen and (max-width:1274px){html body[for="html-export"]:not([data-presentation-mode])[html-show-sidebar-toc] .markdown-preview{padding:2em}}@media screen and (max-width:450px){html body[for="html-export"]:not([data-presentation-mode])[html-show-sidebar-toc] .markdown-preview{width:100%}}html body[for="html-export"]:not([data-presentation-mode]):not([html-show-sidebar-toc]) .markdown-preview{left:50%;transform:translateX(-50%)}html body[for="html-export"]:not([data-presentation-mode]):not([html-show-sidebar-toc]) .md-sidebar-toc{display:none}
/* Please visit the URL below for more information: */
/*   https://shd101wyy.github.io/markdown-preview-enhanced/#/customize-css */

      </style>
    </head>
    <body for="html-export">
      <div class="mume markdown-preview  ">
      <h1 class="mume-header" id="-%E4%B8%80-%E5%87%BD%E6%95%B0%E6%98%AF%E4%BB%80%E4%B9%88">:-: &#x4E00;&#x3001;&#x51FD;&#x6570;&#x662F;&#x4EC0;&#x4E48;</h1>

<ul>
<li>&#x51FD;&#x6570;&#x662F;&#x4E00;&#x6BB5;&#x9700;&#x8981;&#x91CD;&#x590D;&#x6267;&#x884C;&#x7684;&#x4EE3;&#x7801;&#x7247;&#x65AD;</li>
<li>&#x51FD;&#x6570;&#x662F;&#x5B9E;&#x73B0;&#x4EE3;&#x7801;&#x590D;&#x7528;&#x7684;&#x91CD;&#x8981;&#x624B;&#x6BB5;</li>
<li>&#x51FD;&#x6570;&#x662F;&#x73B0;&#x4EE3;&#x7F16;&#x7A0B;&#x8BED;&#x8A00;&#x6700;&#x91CD;&#x8981;&#x7684;&#x57FA;&#x672C;&#x5355;&#x5143;</li>
<li>&#x51FD;&#x6570;&#x6C38;&#x8FDC;&#x662F;&#x7F16;&#x7A0B;&#x7684;&#x6838;&#x5FC3;&#x5DE5;&#x4F5C;</li>
</ul>
<hr>
<h1 class="mume-header" id="-%E4%BA%8C-%E5%87%BD%E6%95%B0%E7%9A%84%E5%88%86%E7%B1%BB">:-: &#x4E8C;&#x3001;&#x51FD;&#x6570;&#x7684;&#x5206;&#x7C7B;</h1>

<p>&#x6839;&#x636E;&#x51FD;&#x6570;&#x7684;&#x63D0;&#x4F9B;&#x8005;(&#x7F16;&#x5199;&#x8005;),&#x5206;&#x4E3A;&#x4E8C;&#x7C7B;</p>
<ul>
<li>&#x7CFB;&#x7EDF;&#x51FD;&#x6570;: &#x7F16;&#x7A0B;&#x8BED;&#x8A00;&#x5F00;&#x53D1;&#x8005;&#x4E8B;&#x5148;&#x5199;&#x597D;&#x63D0;&#x4F9B;&#x7ED9;&#x5F00;&#x53D1;&#x8005;&#x76F4;&#x63A5;&#x4F7F;&#x7528;&#x7684;</li>
<li>&#x81EA;&#x5B9A;&#x4E49;&#x51FD;&#x6570;: &#x7528;&#x6237;&#x6839;&#x636E;&#x81EA;&#x8EAB;&#x9700;&#x6C42;&#xFF0C;&#x5BF9;&#x7CFB;&#x7EDF;&#x529F;&#x80FD;&#x8FDB;&#x884C;&#x6269;&#x5C55;&#xFF0C;&#x6211;&#x4EEC;&#x53C8;&#x79F0;&#x4E3A;&#x65B9;&#x6CD5;</li>
</ul>
<hr>
<h1 class="mume-header" id="-%E4%B8%89-%E5%87%BD%E6%95%B0%E7%9A%84%E5%9F%BA%E6%9C%AC%E8%AF%AD%E6%B3%95">:-:  &#x4E09;&#x3001;&#x51FD;&#x6570;&#x7684;&#x57FA;&#x672C;&#x8BED;&#x6CD5;</h1>

<ul>
<li>&#x8BED;&#x6CD5;: <code>function &#x51FD;&#x6570;&#x540D;(&#x53C2;&#x6570;&#x5217;&#x8868;){&#x51FD;&#x6570;&#x4F53;}</code></li>
<li>&#x5FC5;&#x987B;&#x4F7F;&#x7528;&#x5173;&#x952E;&#x5B57;:<code>function</code> &#x58F0;&#x660E;</li>
<li>&#x51FD;&#x6570;&#x540D;&#x79F0;&#x5FC5;&#x987B;&#x7B26;&#x5408;PHP&#x6807;&#x8BC6;&#x7B26;&#x547D;&#x540D;&#x89C4;&#x8303;</li>
<li>&#x51FD;&#x6570;&#x540D;&#x79F0;<strong>&#x4E0D;&#x533A;&#x5206;&#x5927;&#x5C0F;&#x5199;</strong>,&#x591A;&#x4E2A;&#x5355;&#x8BCD;&#x63A8;&#x8350;&#x4F7F;&#x7528;&#x4E0B;&#x5212;&#x7EBF;&#x8FDE;&#x63A5;</li>
<li>&#x51FD;&#x6570;&#x8C03;&#x7528;&#x8005;&#x4F20;&#x9012;&#x7ED9;&#x51FD;&#x6570;&#x7684;&#x53C2;&#x6570;&#x5FC5;&#x987B;&#x5199;&#x5728;&#x53C2;&#x6570;&#x5217;&#x8868;&#x4E2D;
<ul>
<li>&#x53C2;&#x6570;&#x5217;&#x8868;&#x4E2D;&#x7684;&#x53C2;&#x6570;&#x5FC5;&#x987B;&#x521D;&#x59CB;&#x5316;(&#x5373;&#x6709;&#x503C;)</li>
<li>&#x53C2;&#x6570;&#x5217;&#x8868;&#x53EF;&#x4EE5;&#x4E3A;&#x7A7A;</li>
</ul>
</li>
<li>&#x51FD;&#x6570;&#x4F53;&#x53EF;&#x4EE5;&#x4E3A;&#x7A7A;, &#x4E5F;&#x53EF;&#x4EE5;&#x7531;&#x4E00;&#x6761;&#x6216;&#x591A;&#x6761;&#x8BED;&#x53E5;&#x7EC4;&#x6210;</li>
<li>&#x901A;&#x5E38;&#x51FD;&#x6570;&#x4F53;&#x4F1A;&#x6709;<code>return</code>&#x8FD4;&#x56DE;&#x51FD;&#x6570;&#x6267;&#x884C;&#x7ED3;&#x679C;</li>
</ul>
<pre data-role="codeBlock" data-info="php" class="language-php"><span class="token keyword">function</span> <span class="token function">func_name</span><span class="token punctuation">(</span>&#x53C2;&#x6570;&#x5217;&#x8868;<span class="token punctuation">)</span>
<span class="token punctuation">{</span>
    <span class="token comment">//&#x51FD;&#x6570;&#x4F53;: &#x7531;&#x4E00;&#x6761;&#x6216;&#x591A;&#x6761;&#x8BED;&#x53E5;&#x7EC4;&#x6210;,&#x53EF;&#x4EE5;&#x4E3A;&#x7A7A;</span>
<span class="token punctuation">}</span>
</pre><hr>
<h1 class="mume-header" id="-%E5%9B%9B-%E5%87%BD%E6%95%B0%E4%BD%9C%E7%94%A8%E5%9F%9F">:-:  &#x56DB;&#x3001;&#x51FD;&#x6570;&#x4F5C;&#x7528;&#x57DF;</h1>

<ul>
<li>&#x4F17;&#x6240;&#x5468;&#x77E5;, &#x4F5C;&#x7528;&#x57DF;&#x662F;&#x7528;&#x6765;&#x67E5;&#x627E;&#x53D8;&#x91CF;&#x7684;&#x5DE5;&#x5177;</li>
<li>php&#x4E2D;, &#x53EA;&#x6709;&#x51FD;&#x6570;&#x4F5C;&#x7528;&#x57DF;&#x548C;&#x5168;&#x5C40;&#x4F7F;&#x7528;&#x57DF;</li>
<li>&#x6240;&#x4EE5;&#x51FD;&#x6570;&#x4F5C;&#x7528;&#x57DF;&#x4E2D;&#x7684;&#x53D8;&#x91CF;,&#x5916;&#x90E8;&#x4E0D;&#x53EF;&#x89C1;</li>
<li>&#x5168;&#x5C40;&#x4F5C;&#x7528;&#x57DF;&#x58F0;&#x660E;&#x53D8;&#x91CF;,&#x5728;&#x51FD;&#x6570;&#x4E2D;&#x662F;&#x53EF;&#x89C1;&#x7684;</li>
</ul>
<hr>
<h1 class="mume-header" id="-%E4%BA%94-php%E4%B8%AD%E7%9A%84%E5%87%BD%E6%95%B0%E7%9F%A5%E8%AF%86%E5%AE%9E%E4%BE%8B">:-:  &#x4E94;&#x3001;PHP&#x4E2D;&#x7684;&#x51FD;&#x6570;&#x77E5;&#x8BC6;&#xFF0C;&#x5B9E;&#x4F8B;</h1>

<h3 class="mume-header" id="1-%E5%87%BD%E6%95%B0%E7%9A%84%E5%B8%B8%E8%A7%84%E5%A3%B0%E6%98%8E%E4%B8%8E%E8%B0%83%E7%94%A8">1&#x3001;&#x51FD;&#x6570;&#x7684;&#x5E38;&#x89C4;&#x58F0;&#x660E;&#x4E0E;&#x8C03;&#x7528;</h3>

<pre data-role="codeBlock" data-info="php" class="language-php"><span class="token comment">// &#x4F7F;&#x7528;&#x5173;&#x952E;&#x5B57;function &#x58F0;&#x660E;&#x51FD;&#x6570;</span>
<span class="token comment">// &#x51FD;&#x6570;&#x540D;&#x79F0;&#x5FC5;&#x987B;&#x7B26;&#x5408;php&#x5173;&#x4E8E;&#x6807;&#x8BC6;&#x7B26;&#x7684;&#x7EA6;&#x5B9A;</span>
<span class="token comment">// &#x51FD;&#x6570;&#x9700;&#x8981;&#x63A5;&#x6536;&#x7684;&#x53C2;&#x6570;&#x5199;&#x5230;&#x51FD;&#x6570;&#x540D;&#x540E;&#x7684;&#x4E00;&#x5BF9;&#x62EC;&#x53F7;&#x5185;</span>
<span class="token keyword">function</span> <span class="token function">sum</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
	<span class="token comment">// &#x51FD;&#x6570;&#x53EF;&#x4EE5;&#x6709;return &#x8BED;&#x53E5;,&#x5C06;&#x6267;&#x884C;&#x7ED3;&#x679C;&#x8FD4;&#x56DE;&#x7ED9;&#x8C03;&#x7528;&#x8005;</span>
	<span class="token keyword">return</span> <span class="token number">1</span><span class="token operator">+</span><span class="token number">1</span><span class="token punctuation">;</span>
	<span class="token comment">// &#x5982;&#x679C;&#x4E0D;&#x6709; return &#x8FD4;&#x56DE; null</span>
<span class="token punctuation">}</span>
<span class="token keyword">echo</span> <span class="token function">sum</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
</pre><hr>
<h3 class="mume-header" id="2-%E5%87%BD%E6%95%B0%E7%9A%84%E5%8F%82%E6%95%B0">2&#x3001;&#x51FD;&#x6570;&#x7684;&#x53C2;&#x6570;</h3>

<pre data-role="codeBlock" data-info="php" class="language-php"><span class="token comment">// &#x62EC;&#x53F7;&#x5185;&#x7684;&#x53C2;&#x6570;&#x5217;&#x8868;, &#x662F;&#x5F62;&#x5F0F;&#x53C2;&#x6570;,&#x901A;&#x5E38;&#x4E0E;&#x5B9E;&#x53C2;&#x4E00;&#x4E00;&#x5BF9;&#x5E94;</span>
<span class="token comment">// &#x5B9E;&#x53C2;&#x5FC5;&#x987B;&#x88AB;&#x521D;&#x59CB;&#x5316;, &#x53EF;&#x4EE5;&#x88AB;&#x5B9E;&#x53C2;, &#x4E5F;&#x53EF;&#x4EE5;&#x7528;&#x9ED8;&#x8BA4;&#x503C;</span>
<span class="token keyword">function</span> <span class="token function">sum</span><span class="token punctuation">(</span><span class="token variable">$a</span><span class="token punctuation">,</span> <span class="token variable">$b</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
	<span class="token comment">// $c &#x662F;&#x51FD;&#x6570;&#x81EA;&#x5DF2;&#x7684;&#x79C1;&#x6709;&#x53D8;&#x91CF;, &#x4E5F;&#x53EB;&#x5C40;&#x90E8;&#x53D8;&#x91CF;,&#x5BF9;&#x5916;&#x4E0D;&#x53EF;&#x89C1;</span>
	<span class="token variable">$c</span> <span class="token operator">=</span> <span class="token variable">$a</span> <span class="token operator">+</span> <span class="token variable">$b</span><span class="token punctuation">;</span>
	<span class="token keyword">return</span> <span class="token variable">$c</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token comment">// &#x8C03;&#x7528;</span>
<span class="token comment">// &#x6309;&#x540D;&#x79F0;&#x8C03;&#x7528;,&#x5FC5;&#x987B;&#x5728;&#x51FD;&#x6570;&#x540D;&#x540E;&#x9762;&#x6DFB;&#x52A0;&#x4E00;&#x5BF9;&#x5706;&#x62EC;&#x53F7;</span>
<span class="token comment">// &#x5C06;&#x8C03;&#x7528;&#x53C2;&#x6570;&#x5199;&#x5230;&#x62EC;&#x53F7;&#x5185;</span>
<span class="token comment">// &#x62EC;&#x53F7;&#x5185;&#x7684;&#x53C2;&#x6570;&#x53EB;&#x5B9E;&#x9645;&#x53C2;&#x6570;, &#x7B80;&#x79F0;: &#x5B9E;&#x53C2;</span>
<span class="token keyword">echo</span> <span class="token function">sum</span><span class="token punctuation">(</span><span class="token number">10</span><span class="token punctuation">,</span> <span class="token number">20</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">// &#x51FD;&#x6570;&#x5185;&#x7684;&#x79C1;&#x6709;&#x53D8;&#x91CF;,&#x5916;&#x90E8;&#x4E0D;&#x53EF;&#x8BBF;&#x95EE;</span>
<span class="token comment">// echo $c;</span>
<span class="token comment">// echo &apos;&lt;hr&gt;&apos;;</span>
</pre><hr>
<h3 class="mume-header" id="3-%E5%87%BD%E6%95%B0%E5%8F%82%E6%95%B0%E7%9A%84%E9%BB%98%E8%AE%A4%E5%80%BC">3&#x3001;&#x51FD;&#x6570;&#x53C2;&#x6570;&#x7684;&#x9ED8;&#x8BA4;&#x503C;</h3>

<pre data-role="codeBlock" data-info="php" class="language-php"><span class="token keyword">function</span> <span class="token function">sum</span><span class="token punctuation">(</span><span class="token variable">$a</span> <span class="token operator">=</span> <span class="token number">20</span><span class="token punctuation">,</span> <span class="token variable">$b</span> <span class="token operator">=</span> <span class="token number">30</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
	<span class="token variable">$c</span> <span class="token operator">=</span> <span class="token variable">$a</span> <span class="token operator">+</span> <span class="token variable">$b</span><span class="token punctuation">;</span>
	<span class="token keyword">return</span> <span class="token variable">$c</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">echo</span> <span class="token single-quoted-string string">&apos;&lt;per&gt;&apos;</span><span class="token punctuation">;</span>
<span class="token comment">// &#x5168;&#x90E8;&#x8D4B;&#x503C;,&#x4F7F;&#x7528;&#x81EA;&#x5B9A;&#x4E49;&#x7684;&#x503C;</span>
<span class="token keyword">echo</span> <span class="token function">sum</span><span class="token punctuation">(</span><span class="token number">10</span><span class="token punctuation">,</span> <span class="token number">15</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token single-quoted-string string">&apos;&lt;br&gt;&apos;</span><span class="token punctuation">;</span>
<span class="token comment">// &#x53EA;&#x7ED9;$a&#x8D4B;&#x503C;,$b&#x53D6;&#x9ED8;&#x8BA4;&#x503C;</span>
<span class="token keyword">echo</span> <span class="token function">sum</span><span class="token punctuation">(</span><span class="token number">10</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token single-quoted-string string">&apos;&lt;br&gt;&apos;</span><span class="token punctuation">;</span>
<span class="token comment">// &#x5168;&#x90E8;&#x53D6;&#x9ED8;&#x8BA4;&#x503C;</span>
<span class="token keyword">echo</span> <span class="token function">sum</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token single-quoted-string string">&apos;&lt;br&gt;&apos;</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token single-quoted-string string">&apos;&lt;hr&gt;&apos;</span><span class="token punctuation">;</span>
</pre><hr>
<h3 class="mume-header" id="4-%E5%87%BD%E6%95%B0%E4%B8%8D%E5%9B%BA%E5%AE%9A%E5%8F%82%E6%95%B0%E6%95%B0%E9%87%8F">4&#x3001;&#x51FD;&#x6570;&#x4E0D;&#x56FA;&#x5B9A;&#x53C2;&#x6570;&#x6570;&#x91CF;</h3>

<ul>
<li>func_num_args &#x83B7;&#x53D6;&#x5B9E;&#x53C2;&#x7684;&#x6570;&#x91CF;</li>
<li>func_get_args &#x83B7;&#x53D6;&#x5B9E;&#x53C2;&#x7684;&#x503C;&#xFF08;&#x6570;&#x7EC4;&#xFF09;</li>
</ul>
<pre data-role="codeBlock" data-info="php" class="language-php"><span class="token comment">// &#x4E00;&#x3001;&#x5F62;&#x53C2;&#x5217;&#x8868;&#x53EA;&#x662F;&#x5360;&#x4F4D;&#x7B26;,&#x53EF;&#x4EE5;&#x5728;&#x51FD;&#x6570;&#x4E2D;&#x83B7;&#x53D6;&#x8C03;&#x7528;&#x7684;&#x5B9E;&#x53C2;</span>
<span class="token keyword">function</span> <span class="token function">sum1</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
	<span class="token comment">// &#x83B7;&#x53D6;&#x5B9E;&#x53C2;&#x7684;&#x6570;&#x91CF;</span>
	<span class="token variable">$argNum</span> <span class="token operator">=</span> <span class="token function">func_num_args</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">// &#x65E0;&#x53C2;&#x6570;</span>
	<span class="token keyword">echo</span> <span class="token variable">$argNum</span><span class="token punctuation">;</span>

	<span class="token comment">// &#x83B7;&#x53D6;&#x5B9E;&#x53C2;&#x7EC4;&#x6210;&#x7684;&#x6570;&#x7EC4;</span>
	<span class="token variable">$argArr</span> <span class="token operator">=</span> <span class="token function">func_get_args</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">// &#x65E0;&#x53C2;&#x6570;</span>
	<span class="token function">print_r</span><span class="token punctuation">(</span><span class="token variable">$argArr</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

	<span class="token comment">// &#x83B7;&#x53D6;&#x6BCF;&#x4E00;&#x4E2A;&#x53C2;&#x6570;</span>
	<span class="token keyword">echo</span> <span class="token function">func_get_arg</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">// &#x7B2C;&#x4E00;&#x4E2A;&#x5B9E;&#x53C2;</span>
	<span class="token keyword">echo</span> <span class="token function">func_get_arg</span><span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">// &#x7B2C;&#x4E8C;&#x4E2A;&#x5B9E;&#x53C2;</span>

	<span class="token comment">// 1&#xFF0C;&#x8BA1;&#x7B97;&#x4E8C;&#x4E2A;&#x6570;&#x7684;&#x548C;</span>
	<span class="token variable">$a</span> <span class="token operator">=</span> <span class="token function">func_get_arg</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token variable">$b</span> <span class="token operator">=</span> <span class="token function">func_get_arg</span><span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
	<span class="token keyword">return</span> <span class="token variable">$a</span> <span class="token operator">+</span> <span class="token variable">$b</span><span class="token punctuation">;</span>

	<span class="token comment">// 2&#xFF0C;&#x4F7F;&#x7528;&#x5B9E;&#x53C2;&#x6570;&#x7EC4;&#x6765;&#x7B80;&#x5316;&#xFF0C;&#x8BA1;&#x7B97;&#x4E8C;&#x4E2A;&#x6570;&#x7684;&#x548C;</span>
	<span class="token variable">$total</span> <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span>
	<span class="token keyword">foreach</span> <span class="token punctuation">(</span><span class="token variable">$argArr</span> <span class="token keyword">as</span> <span class="token variable">$value</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
		<span class="token variable">$total</span> <span class="token operator">+</span><span class="token operator">=</span> <span class="token variable">$value</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>
	<span class="token keyword">return</span> <span class="token variable">$total</span><span class="token punctuation">;</span>

	<span class="token comment">// 3&#xFF0C;&#x4EE5;&#x4E0A;&#x6570;&#x7EC4;&#x6C42;&#x548C;,&#x53EF;&#x4EE5;&#x4F7F;&#x7528;&#x6570;&#x7EC4;&#x51FD;&#x6570;arrya_sum()&#x7B80;&#x5316;&#xFF0C;&#x8BA1;&#x7B97;&#x4E8C;&#x4E2A;&#x6570;&#x7684;&#x548C;</span>
	<span class="token keyword">return</span> <span class="token function">array_sum</span><span class="token punctuation">(</span><span class="token variable">$argArr</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">echo</span> <span class="token function">sum1</span><span class="token punctuation">(</span><span class="token number">10</span><span class="token punctuation">,</span> <span class="token number">20</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token single-quoted-string string">&apos;&lt;br&gt;&apos;</span><span class="token punctuation">;</span>

<span class="token comment">// &#x51FD;&#x6570;&#x5185;&#x90E8;&#x4F7F;&#x7528;&#x53C2;&#x6570;&#x5FAA;&#x73AF;&#x65F6;&#x53EF;&#x4EE5;&#x8BA1;&#x7B97;&#x4EFB;&#x610F;&#x6570;&#x91CF;&#x7684;&#x6570;&#x636E;&#x4E4B;&#x548C;</span>
<span class="token keyword">echo</span> <span class="token function">sum1</span><span class="token punctuation">(</span><span class="token number">10</span><span class="token punctuation">,</span> <span class="token number">20</span><span class="token punctuation">,</span> <span class="token number">30</span><span class="token punctuation">,</span> <span class="token number">40</span><span class="token punctuation">,</span> <span class="token number">50</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token single-quoted-string string">&apos;&lt;hr&gt;&apos;</span><span class="token punctuation">;</span>

<span class="token comment">// &#x4E8C;&#x3001;php7, &#x63D0;&#x4F9B;&#x4E86;&#x4E00;&#x79CD;&#x53EF;&#x53D8;&#x957F;&#x53C2;&#x6570;, &#x53EF;&#x4EE5;&#x66FF;&#x4EE3;func_get_args()&#x51FD;&#x6570;</span>
<span class="token keyword">function</span> <span class="token function">sum2</span><span class="token punctuation">(</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token variable">$params</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
	<span class="token comment">// &#x53D8;&#x957F;&#x53C2;&#x6570;&#x7684;&#x6807;&#x793A; ...</span>
	<span class="token comment">// &#x5C06;&#x5B9E;&#x53C2;&#x5168;&#x90E8;&#x6253;&#x5305;&#x5230;&#x5F62;&#x53C2;&#x53D8;&#x91CF;$params&#x4E2D;</span>
	<span class="token function">print_r</span><span class="token punctuation">(</span><span class="token variable">$params</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

	<span class="token comment">// &#x5B9E;&#x73B0;&#x4E0A;&#x4F8B;&#x7684;&#x7D2F;&#x52A0;&#x64CD;&#x4F5C;</span>
	<span class="token variable">$total</span> <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span>
	<span class="token keyword">foreach</span> <span class="token punctuation">(</span><span class="token variable">$params</span> <span class="token keyword">as</span> <span class="token variable">$value</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
		<span class="token variable">$total</span> <span class="token operator">+</span><span class="token operator">=</span> <span class="token variable">$value</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span>
	<span class="token keyword">return</span> <span class="token variable">$total</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">echo</span> <span class="token function">sum2</span><span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">,</span><span class="token number">2</span><span class="token punctuation">,</span><span class="token number">3</span><span class="token punctuation">,</span><span class="token number">4</span><span class="token punctuation">,</span><span class="token number">5</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token single-quoted-string string">&apos;&lt;hr&gt;&apos;</span><span class="token punctuation">;</span>

<span class="token comment">// &#x4E09;&#x3001;&#x53D8;&#x957F;&#x53C2;&#x6570;&#x7684;&#x4E00;&#x4E2A;&#x5E94;&#x7528;&#x573A;&#x666F;</span>
<span class="token keyword">function</span> <span class="token function">sum3</span><span class="token punctuation">(</span><span class="token variable">$a</span><span class="token punctuation">,</span> <span class="token variable">$b</span><span class="token punctuation">,</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token variable">$c</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
	<span class="token comment">// $a=1, $b=2, &#x5269;&#x4E0B;&#x53C2;&#x6570;&#x5168;&#x90E8;&#x6253;&#x5305;&#x5230;&#x6570;&#x7EC4;$c&#x4E2D;, $c=[3,4,5,6]</span>
	<span class="token keyword">return</span> <span class="token single-quoted-string string">&apos;$a=&apos;</span><span class="token punctuation">.</span><span class="token variable">$a</span><span class="token punctuation">.</span><span class="token single-quoted-string string">&apos;, $b=&apos;</span><span class="token punctuation">.</span><span class="token variable">$b</span> <span class="token punctuation">.</span><span class="token single-quoted-string string">&apos;&lt;br&gt;&apos;</span><span class="token punctuation">.</span> <span class="token function">print_r</span><span class="token punctuation">(</span><span class="token variable">$c</span><span class="token punctuation">,</span> <span class="token boolean">true</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">echo</span> <span class="token function">sum3</span><span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">,</span><span class="token number">2</span><span class="token punctuation">,</span><span class="token number">3</span><span class="token punctuation">,</span><span class="token number">4</span><span class="token punctuation">,</span><span class="token number">5</span><span class="token punctuation">,</span><span class="token number">6</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token single-quoted-string string">&apos;&lt;hr&gt;&apos;</span><span class="token punctuation">;</span>

<span class="token comment">// &#x56DB;&#x3001;&#x53D8;&#x957F;&#x7684;&#x5B9E;&#x53C2;</span>
<span class="token keyword">function</span> <span class="token function">sum4</span><span class="token punctuation">(</span><span class="token variable">$a</span><span class="token punctuation">,</span><span class="token variable">$b</span><span class="token punctuation">,</span><span class="token variable">$c</span><span class="token punctuation">,</span><span class="token variable">$d</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
	<span class="token keyword">return</span> <span class="token variable">$a</span><span class="token operator">+</span><span class="token variable">$b</span><span class="token operator">+</span><span class="token variable">$c</span><span class="token operator">+</span><span class="token variable">$d</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token variable">$arr</span> <span class="token operator">=</span> <span class="token punctuation">[</span><span class="token number">6</span><span class="token punctuation">,</span><span class="token number">7</span><span class="token punctuation">,</span><span class="token number">8</span><span class="token punctuation">]</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token function">sum4</span><span class="token punctuation">(</span><span class="token number">2</span><span class="token punctuation">,</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token variable">$arr</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token single-quoted-string string">&apos;&lt;br&gt;&apos;</span><span class="token punctuation">;</span>

<span class="token comment">// $arr &#x4F1A;&#x7528;... &#x81EA;&#x52A8;&#x5C55;&#x5F00;, &#x7B49;&#x4EF7;&#x4E8E;&#x8FD9;&#x6837;&#x8C03;&#x7528;</span>
<span class="token keyword">echo</span> <span class="token function">sum4</span><span class="token punctuation">(</span><span class="token number">2</span><span class="token punctuation">,</span><span class="token number">6</span><span class="token punctuation">,</span><span class="token number">7</span><span class="token punctuation">,</span><span class="token number">8</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token single-quoted-string string">&apos;&lt;hr&gt;&apos;</span><span class="token punctuation">;</span>

<span class="token comment">// &#x4E94;&#x3001;php7, &#x53EF;&#x4EE5;&#x5BF9;&#x53C2;&#x6570;&#x7C7B;&#x578B;&#x8FDB;&#x884C;&#x9650;&#x5236;</span>
<span class="token keyword">function</span> <span class="token function">sum5</span><span class="token punctuation">(</span>int <span class="token variable">$a</span><span class="token punctuation">,</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token variable">$arr</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
	<span class="token comment">// &#x9650;&#x5236;&#x4E86;&#x53C2;&#x6570;&#x6574;&#x6570;&#x7C7B;&#x578B;, 2.5&#x8F6C;&#x4E3A;2, &apos;5&apos; &#x88AB;&#x5F3A;&#x5236;&#x8F6C;&#x6362;&#x6210;&#x6574;&#x6570;5</span>
	<span class="token keyword">return</span> <span class="token variable">$a</span> <span class="token operator">+</span> <span class="token function">array_sum</span><span class="token punctuation">(</span><span class="token variable">$arr</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">echo</span> <span class="token function">sum5</span><span class="token punctuation">(</span><span class="token number">2.5</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">,</span> <span class="token number">4</span><span class="token punctuation">,</span> <span class="token single-quoted-string string">&apos;5&apos;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
</pre><hr>
<h3 class="mume-header" id="5-%E5%87%BD%E6%95%B0%E7%9A%84%E8%BF%94%E5%9B%9E%E5%80%BC">5&#x3001;&#x51FD;&#x6570;&#x7684;&#x8FD4;&#x56DE;&#x503C;</h3>

<pre data-role="codeBlock" data-info="php" class="language-php"><span class="token comment">// 1&#x3001;return &#x8FD4;&#x56DE;&#x503C;</span>
<span class="token keyword">function</span> <span class="token function">demo1</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
	<span class="token comment">// &#x53EF;&#x4EE5;&#x4F7F;&#x7528;&#x8FD4;&#x56DE;&#x8BED;&#x53E5;: return &#x8FD4;&#x56DE;&#x6267;&#x884C;&#x7ED3;&#x679C;</span>
	<span class="token keyword">return</span> <span class="token single-quoted-string string">&apos;Hello PHP&apos;</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token keyword">echo</span> <span class="token function">demo1</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token single-quoted-string string">&apos;&lt;hr&gt;&apos;</span><span class="token punctuation">;</span>

<span class="token comment">// 2&#x3001;&#x5982;&#x679C;&#x6CA1;&#x6709;return , &#x9ED8;&#x8BA4;&#x8FD4;&#x56DE; null</span>
<span class="token keyword">function</span> <span class="token function">demo2</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span>

<span class="token punctuation">}</span>
<span class="token comment">// &#x68C0;&#x6D4B;&#x8FD4;&#x56DE;&#x503C;&#x7684;&#x7C7B;&#x578B;</span>
<span class="token keyword">echo</span> <span class="token function">is_null</span><span class="token punctuation">(</span><span class="token function">demo2</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span> <span class="token operator">?</span> <span class="token single-quoted-string string">&apos;&#x8FD4;&#x56DE;NULL&apos;</span> <span class="token punctuation">:</span> <span class="token single-quoted-string string">&apos;&#x6CA1;&#x6709;&#x8FD4;&#x56DE;NULL&apos;</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token single-quoted-string string">&apos;&lt;hr&gt;&apos;</span><span class="token punctuation">;</span>

<span class="token comment">// 3&#x3001;&#x51FD;&#x6570;&#x4E0D;&#x5141;&#x8BB8;&#x8FD4;&#x56DE;&#x591A;&#x4E2A;&#x503C;</span>
<span class="token keyword">function</span> <span class="token function">demo3</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
	<span class="token variable">$a</span> <span class="token operator">=</span> <span class="token number">10</span><span class="token punctuation">;</span>
	<span class="token variable">$b</span> <span class="token operator">=</span> <span class="token number">20</span><span class="token punctuation">;</span>
	<span class="token comment">// return &#x8FD4;&#x56DE;&#x591A;&#x4E2A;&#x503C;&#x62A5;&#x9519;</span>
	<span class="token keyword">return</span> <span class="token variable">$a</span><span class="token punctuation">,</span><span class="token variable">$b</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token keyword">echo</span> <span class="token function">demo3</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">// 4&#x3001;&#x51FD;&#x6570;&#x8FD4;&#x56DE;&#x591A;&#x4E2A;&#x503C;&#xFF0C;&#x7528;&#x6570;&#x7EC4;&#x8FD4;&#x56DE;</span>
<span class="token keyword">function</span> <span class="token function">demo4</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
	<span class="token variable">$a</span> <span class="token operator">=</span> <span class="token number">10</span><span class="token punctuation">;</span>
	<span class="token variable">$b</span> <span class="token operator">=</span> <span class="token number">20</span><span class="token punctuation">;</span>
	<span class="token keyword">return</span> <span class="token punctuation">[</span><span class="token variable">$a</span><span class="token punctuation">,</span> <span class="token variable">$b</span><span class="token punctuation">]</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token keyword">echo</span> <span class="token single-quoted-string string">&apos;&lt;pre&gt;&apos;</span> <span class="token punctuation">.</span> <span class="token function">print_r</span><span class="token punctuation">(</span><span class="token function">demo4</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span><span class="token boolean">true</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">// 5&#x3001;php7&#x4E2D;, &#x53EF;&#x4EE5;&#x9650;&#x5B9A;&#x51FD;&#x6570;&#x7684;&#x8FD4;&#x56DE;&#x7C7B;&#x578B;</span>
<span class="token keyword">function</span> <span class="token function">demo5</span><span class="token punctuation">(</span><span class="token variable">$a</span><span class="token punctuation">,</span> <span class="token variable">$b</span><span class="token punctuation">)</span> <span class="token punctuation">:</span>int<span class="token punctuation">{</span>
	<span class="token keyword">return</span> <span class="token variable">$a</span> <span class="token operator">+</span> <span class="token variable">$b</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token comment">// &#x4E0D;&#x9650;&#x5B9A;&#x8FD4;&#x56DE;&#x7C7B;&#x578B;,&#x8F93;&#x51FA;: 4.7, &#x9650;&#x5B9A;&#x540E;&#x8FD4;&#x56DE;: 4</span>
<span class="token keyword">echo</span> <span class="token function">demo5</span><span class="token punctuation">(</span><span class="token number">1.4</span><span class="token punctuation">,</span> <span class="token number">3.3</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
</pre><hr>
<h3 class="mume-header" id="6-%E5%87%BD%E6%95%B0%E4%B8%AD%E7%9A%84%E5%8F%98%E9%87%8F%E8%AE%BF%E9%97%AE">6&#x3001;&#x51FD;&#x6570;&#x4E2D;&#x7684;&#x53D8;&#x91CF;&#x8BBF;&#x95EE;</h3>

<pre data-role="codeBlock" data-info="php" class="language-php"><span class="token comment">// 1&#x3001;&#x51FD;&#x6570;&#x4E2D;&#x7684;&#x53D8;&#x91CF;&#x8BBF;&#x95EE;</span>
<span class="token variable">$site</span> <span class="token operator">=</span> <span class="token single-quoted-string string">&apos;www.php.cn&apos;</span><span class="token punctuation">;</span>
<span class="token keyword">function</span> <span class="token function">demo1</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
	<span class="token comment">// &#x51FD;&#x6570;&#x4E2D;&#x4E0D;&#x80FD;&#x76F4;&#x63A5;&#x8BBF;&#x95EE;&#x5916;&#x90E8;&#x53D8;&#x91CF;</span>
	<span class="token keyword">return</span> <span class="token variable">$site</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token keyword">echo</span> <span class="token function">demo1</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token single-quoted-string string">&apos;&lt;hr&gt;&apos;</span><span class="token punctuation">;</span>

<span class="token comment">// 2&#x3001;&#x51FD;&#x6570;&#x4E2D;&#x7684;&#x5168;&#x5C40;&#x53D8;&#x91CF;&#x8BBF;&#x95EE;</span>
<span class="token variable">$site</span> <span class="token operator">=</span> <span class="token single-quoted-string string">&apos;www.php.cn&apos;</span><span class="token punctuation">;</span>
<span class="token keyword">function</span> <span class="token function">demo2</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
	<span class="token comment">// &#x5728;&#x51FD;&#x6570;&#x4E2D;&#x4F7F;&#x7528;global&#x5173;&#x952E;&#x5B57;&#x58F0;&#x660E;&#x4E00;&#x4E0B;$site&#x662F;&#x4E00;&#x4E2A;&#x5168;&#x5C40;&#x53D8;&#x91CF;</span>
	<span class="token comment">// &#x8FD9;&#x6837;, &#x51FD;&#x6570;&#x4E2D;&#x5C31;&#x53EF;&#x8BC6;&#x522B;&#x51FA;&#x8FD9;&#x4E2A;$site&#x53D8;&#x91CF;</span>
	<span class="token keyword">global</span> <span class="token variable">$site</span><span class="token punctuation">;</span>
	<span class="token comment">// &#x51FD;&#x6570;&#x4E2D;&#x4E0D;&#x80FD;&#x76F4;&#x63A5;&#x8BBF;&#x95EE;&#x5916;&#x90E8;&#x53D8;&#x91CF;</span>
	<span class="token keyword">return</span> <span class="token variable">$site</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token keyword">echo</span> <span class="token single-quoted-string string">&apos;&lt;per&gt;&apos;</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token function">demo2</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token single-quoted-string string">&apos;&lt;hr&gt;&apos;</span><span class="token punctuation">;</span>

<span class="token comment">// 3&#x3001;&#x51FD;&#x6570;&#x5916;&#x90E8;&#x58F0;&#x660E;&#x7684;&#x53D8;&#x91CF;&#xFF0C;&#x4F1A;&#x81EA;&#x52A8;&#x6210;&#x4E3A;&#x8D85;&#x5168;&#x5C40;&#x53D8;&#x91CF;&#x6570;&#x7EC4;$GLOBALS&#x7684;&#x6210;&#x5458;</span>
<span class="token variable">$site</span> <span class="token operator">=</span> <span class="token single-quoted-string string">&apos;www.php.cn&apos;</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token global">$GLOBALS</span><span class="token punctuation">[</span><span class="token single-quoted-string string">&apos;site&apos;</span><span class="token punctuation">]</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token single-quoted-string string">&apos;&lt;hr&gt;&apos;</span><span class="token punctuation">;</span>
<span class="token keyword">function</span> <span class="token function">demo3</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
	<span class="token comment">// &#x8D85;&#x5168;&#x5C40;&#x53D8;&#x91CF;&#x4E0D;&#x53D7;&#x4F5C;&#x7528;&#x57DF;&#x9650;&#x5236;,&#x53EF;&#x4EE5;&#x5728;&#x811A;&#x672C;&#x7684;&#x4EFB;&#x4F55;&#x5730;&#x65B9;&#x4F7F;&#x7528;,&#x5F53;&#x7136;&#x4E5F;&#x5305;&#x62EC;&#x51FD;&#x6570;&#x5185;</span>
	<span class="token keyword">return</span> <span class="token global">$GLOBALS</span><span class="token punctuation">[</span><span class="token single-quoted-string string">&apos;site&apos;</span><span class="token punctuation">]</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token keyword">echo</span> <span class="token function">demo3</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">// 4&#x3001;&#x5E38;&#x91CF;&#x4E5F;&#x4E0D;&#x53D7;&#x4F5C;&#x7528;&#x57DF;&#x7684;&#x9650;&#x5236;,&#x53EF;&#x4EE5;&#x5728;&#x811A;&#x672C;&#x7684;&#x4EFB;&#x4F55;&#x5730;&#x65B9;&#x4F7F;&#x7528;</span>
<span class="token comment">// &#x6240;&#x8C13;&#x5E38;&#x91CF;,&#x53EF;&#x4EE5;&#x7406;&#x89E3;&#x4E3A;&#x53EA;&#x8BFB;&#x53D8;&#x91CF;, &#x4E00;&#x7ECF;&#x5B9A;&#x4E49;&#x4E0D;&#x5141;&#x8BB8;&#x66F4;&#x65B0;&#x6216;&#x5220;&#x9664;</span>
<span class="token function">define</span><span class="token punctuation">(</span><span class="token single-quoted-string string">&apos;SITE_NAME&apos;</span><span class="token punctuation">,</span> <span class="token single-quoted-string string">&apos;PHP&#x4E2D;&#x6587;&#x7F51;&apos;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">function</span> <span class="token function">demo4</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
	<span class="token keyword">return</span> <span class="token constant">SITE_NAME</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token keyword">echo</span> <span class="token function">demo4</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">// 5&#x3001;&#x5916;&#x90E8;&#x5982;&#x4F55;&#x8BBF;&#x95EE;&#x51FD;&#x6570;&#x7684;&#x79C1;&#x6709;&#x53D8;&#x91CF;</span>
<span class="token keyword">function</span> <span class="token function">demo5</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
	<span class="token variable">$email</span> <span class="token operator">=</span> <span class="token single-quoted-string string">&apos;ouyangke@php.cn&apos;</span><span class="token punctuation">;</span>
	<span class="token comment">// &#x901A;&#x8FC7;return &#x8FD4;&#x56DE;&#x79C1;&#x6709;&#x53D8;&#x91CF;&#x5230;&#x5916;&#x90E8;&#x8C03;&#x7528;&#x8005;</span>
	<span class="token keyword">return</span> <span class="token variable">$email</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token keyword">echo</span> <span class="token function">demo5</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
</pre><hr>
<h3 class="mume-header" id="7-%E5%8C%BF%E5%90%8D%E5%87%BD%E6%95%B0%E4%B8%8E%E9%97%AD%E5%8C%85">7&#x3001;&#x533F;&#x540D;&#x51FD;&#x6570;&#x4E0E;&#x95ED;&#x5305;</h3>

<ul>
<li>&#x5B98;&#x7F51;&#x89E3;&#x91CA;:
<ul>
<li>&#x533F;&#x540D;&#x51FD;&#x6570;&#xFF08;Anonymous functions&#xFF09;&#xFF0C;&#x4E5F;&#x53EB;&#x95ED;&#x5305;&#x51FD;&#x6570;&#xFF08;closures&#xFF09;</li>
<li>&#x5141;&#x8BB8; &#x4E34;&#x65F6;&#x521B;&#x5EFA;&#x4E00;&#x4E2A;&#x6CA1;&#x6709;&#x6307;&#x5B9A;&#x540D;&#x79F0;&#x7684;&#x51FD;&#x6570;&#x3002;&#x6700;&#x7ECF;&#x5E38;&#x7528;&#x4F5C;&#x56DE;&#x8C03;&#x51FD;&#x6570;&#xFF08;callback&#xFF09;&#x53C2;&#x6570;&#x7684;&#x503C;&#x3002;</li>
<li>&#x5F53;&#x7136;&#xFF0C;&#x4E5F;&#x6709;&#x5176;&#x5B83;&#x5E94;&#x7528;&#x7684;&#x60C5;&#x51B5;&#x3002;&#x533F;&#x540D;&#x51FD;&#x6570;&#x76EE;&#x524D;&#x662F;&#x901A;&#x8FC7; Closure &#x7C7B;&#x6765;&#x5B9E;&#x73B0;&#x7684;&#x3002;</li>
</ul>
</li>
</ul>
<pre data-role="codeBlock" data-info="php" class="language-php"><span class="token comment">// 1&#x3001;&#x533F;&#x540D;&#x51FD;&#x6570;, &#x505A;&#x4E3A;&#x503C;&#x6765;&#x4F7F;&#x7528;</span>
<span class="token variable">$sum</span> <span class="token operator">=</span> <span class="token keyword">function</span> <span class="token punctuation">(</span><span class="token variable">$a</span><span class="token punctuation">,</span> <span class="token variable">$b</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
	<span class="token keyword">return</span> <span class="token variable">$a</span> <span class="token operator">+</span> <span class="token variable">$b</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token variable">$sum</span><span class="token punctuation">(</span><span class="token number">5</span><span class="token punctuation">,</span><span class="token number">6</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">// 2&#x3001;&#x533F;&#x540D;&#x51FD;&#x6570;: &#x505A;&#x4E3A;&#x56DE;&#x8C03;&#x53C2;&#x6570;&#x6765;&#x4F7F;&#x7528;</span>
<span class="token variable">$arr</span> <span class="token operator">=</span> <span class="token punctuation">[</span><span class="token number">3</span><span class="token punctuation">,</span><span class="token number">1</span><span class="token punctuation">,</span><span class="token number">6</span><span class="token punctuation">,</span><span class="token number">2</span><span class="token punctuation">,</span><span class="token number">9</span><span class="token punctuation">]</span><span class="token punctuation">;</span>
<span class="token function">usort</span><span class="token punctuation">(</span><span class="token variable">$arr</span><span class="token punctuation">,</span> <span class="token keyword">function</span> <span class="token punctuation">(</span><span class="token variable">$a</span><span class="token punctuation">,</span> <span class="token variable">$b</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
	<span class="token comment">// &gt;0, &#x7531;&#x5C0F;&#x5230;&#x5927;</span>
	<span class="token comment">// =0, &#x76F8;&#x7B49;</span>
	<span class="token comment">// &lt;0, &#x7531;&#x5927;&#x5230;&#x5C0F;</span>
	<span class="token keyword">return</span> <span class="token variable">$a</span> <span class="token operator">-</span> <span class="token variable">$b</span><span class="token punctuation">;</span> <span class="token comment">// asc</span>
	<span class="token comment">// return $b - $a; // desc</span>
<span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token function">print_r</span><span class="token punctuation">(</span><span class="token variable">$arr</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">// 3&#x3001;php7&#x4E2D;, &#x5BF9;&#x4E8E;&#x8FD9;&#x7C7B;&#x6BD4;&#x8F83;&#x8FD0;&#x7B97;, &#x6709;&#x4E00;&#x4E2A;&#x66F4;&#x7B80;&#x6D01;&#x7684;&#x8BED;&#x6CD5;:&#x592A;&#x7A7A;&#x8239;&#x64CD;&#x4F5C;&#x7B26;</span>
<span class="token variable">$arr</span> <span class="token operator">=</span> <span class="token punctuation">[</span><span class="token number">3</span><span class="token punctuation">,</span><span class="token number">1</span><span class="token punctuation">,</span><span class="token number">6</span><span class="token punctuation">,</span><span class="token number">2</span><span class="token punctuation">,</span><span class="token number">9</span><span class="token punctuation">]</span><span class="token punctuation">;</span>
<span class="token function">usort</span><span class="token punctuation">(</span><span class="token variable">$arr</span><span class="token punctuation">,</span> <span class="token keyword">function</span> <span class="token punctuation">(</span><span class="token variable">$a</span><span class="token punctuation">,</span> <span class="token variable">$b</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
	<span class="token keyword">return</span> <span class="token variable">$a</span> <span class="token operator">&lt;=</span><span class="token operator">&gt;</span> <span class="token variable">$b</span><span class="token punctuation">;</span>
	<span class="token keyword">return</span> <span class="token variable">$b</span> <span class="token operator">&lt;=</span><span class="token operator">&gt;</span> <span class="token variable">$a</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token function">print_r</span><span class="token punctuation">(</span><span class="token variable">$arr</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">// 4&#x3001;&#x83B7;&#x53D6;&#x7236;&#x4F5C;&#x7528;&#x57DF;&#x4E2D;&#x7684;&#x53D8;&#x91CF;</span>
<span class="token variable">$name</span> <span class="token operator">=</span> <span class="token single-quoted-string string">&apos;&#x6B27;&#x9633;&#x514B;&apos;</span><span class="token punctuation">;</span>
<span class="token variable">$f1</span> <span class="token operator">=</span> <span class="token keyword">function</span> <span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
	<span class="token comment">// &#x76F4;&#x63A5;&#x83B7;&#x53D6;&#x5916;&#x90E8;&#x53D8;&#x91CF;,&#x662F;&#x53D6;&#x4E0D;&#x5230;&#x7684;</span>
	<span class="token keyword">return</span> <span class="token variable">$name</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token variable">$f1</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">// 5&#x3001;&#x83B7;&#x53D6;&#x7236;&#x4F5C;&#x7528;&#x57DF;&#x4E2D;&#x7684;&#x53D8;&#x91CF;</span>
<span class="token variable">$name</span> <span class="token operator">=</span> <span class="token single-quoted-string string">&apos;&#x6B27;&#x9633;&#x514B;&apos;</span><span class="token punctuation">;</span>
<span class="token variable">$f2</span> <span class="token operator">=</span> <span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token keyword">use</span> <span class="token punctuation">(</span><span class="token variable">$email</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
	<span class="token keyword">return</span> <span class="token variable">$email</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token variable">$f2</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">// 6&#x3001;&#x5927;&#x591A;&#x6570;&#x60C5;&#x51B5;&#x4E0B;, &#x6211;&#x4EEC;&#x4F1A;&#x5728;&#x95ED;&#x5305;&#x51FD;&#x6570;&#x4E2D;&#x5BF9;&#x5916;&#x90E8;&#x53D8;&#x91CF;&#x8FDB;&#x884C;&#x66F4;&#x65B0;</span>
<span class="token comment">// &#x8FD9;&#x65F6;&#x53EF;&#x4EE5;&#x5C06;&#x5916;&#x90E8;&#x53D8;&#x91CF;&#x4EE5;&#x5F15;&#x7528;&#x7684;&#x65B9;&#x5F0F;&#x4F20;&#x5165;</span>
<span class="token comment">// &#x9ED8;&#x8BA4;&#x60C5;&#x51B5;&#x4E0B;&#xFF0C;&#x53C2;&#x6570;&#x662F;&#x4EE5;&#x503C;&#x7684;&#x65B9;&#x5F0F;&#x4F20;&#x5230;&#x51FD;&#x6570;&#x4E2D;,&#x6240;&#x8C13;&#x5F15;&#x7528;, &#x5C31;&#x662F;&#x5185;&#x5916;&#x90E8;&#x5B9E;&#x9645;&#x8BBF;&#x95EE;&#x7684;&#x662F;&#x540C;&#x4E00;&#x4E2A;&#x53D8;&#x91CF;</span>
<span class="token comment">// &#x53EA;&#x9700;&#x8981;&#x5728;&#x53C2;&#x6570;&#x524D;&#x6DFB;&#x52A0;&#x4E00;&#x4E2A;&#x53D6;&#x5730;&#x5740;&#x7B26;: &amp; &#x5373;&#x53EF;</span>
<span class="token variable">$name</span> <span class="token operator">=</span> <span class="token single-quoted-string string">&apos;&#x6B27;&#x9633;&#x514B;&apos;</span><span class="token punctuation">;</span>
<span class="token variable">$f3</span> <span class="token operator">=</span> <span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token keyword">use</span> <span class="token punctuation">(</span><span class="token operator">&amp;</span><span class="token variable">$name</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
	<span class="token keyword">return</span> <span class="token variable">$name</span> <span class="token operator">=</span> <span class="token single-quoted-string string">&apos;&#x9EC4;&#x84C9;&apos;</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token variable">$f3</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

<span class="token comment">// 7&#x3001;&#x5728;&#x5B50;&#x51FD;&#x6570;&#x4E2D;&#x7684;&#x4F7F;&#x7528;</span>
<span class="token keyword">function</span> <span class="token function">demo</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
	<span class="token variable">$name</span> <span class="token operator">=</span> <span class="token single-quoted-string string">&apos;&#x6B27;&#x9633;&#x514B;&apos;</span><span class="token punctuation">;</span>
	<span class="token keyword">return</span> <span class="token keyword">function</span> <span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token keyword">use</span> <span class="token punctuation">(</span><span class="token variable">$name</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
		<span class="token keyword">return</span> <span class="token variable">$name</span><span class="token punctuation">;</span>
	<span class="token punctuation">}</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token comment">//demo()&#x8FD4;&#x56DE;&#x7ED3;&#x679C;&#x662F;&#x51FD;&#x6570;, &#x6240;&#x4EE5;&#x9700;&#x8981;&#x518D;&#x6B21;&#x8C03;&#x7528;</span>
<span class="token keyword">echo</span> <span class="token function">demo</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
</pre><blockquote>
<p>[danger] &#x5907;&#xFF1A;&#x5C06;&#x4E00;&#x4E2A;&#x51FD;&#x6570;&#x7684;&#x8FD4;&#x56DE;&#x503C;,&#x8BBE;&#x7F6E;&#x4E3A;&#x4E00;&#x4E2A;&#x95ED;&#x5305;&#x51FD;&#x6570;, &#x5728;&#x5B9E;&#x9645;&#x5F00;&#x53D1;&#x4E2D;&#x975E;&#x5E38;&#x6709;&#x7528;&#x7684;, &#x7B49;&#x540E;&#x9762;&#x9047;&#x5230;&#x5177;&#x4F53;&#x5E94;&#x7528;&#x573A;&#x666F;&#x65F6;&#x518D;&#x7EC6;&#x8BF4;</p>
</blockquote>

      </div>
      
      
    
    
    
    
    
    
    
    
  
    </body></html>